Deviation measuring apparatus

ABSTRACT

This invention intends to provide a deviation measuring apparatus which enables to select a bat capable of bringing a hitting position of a ball to near the center core position of a baseball bat or correct a batting form of a batter by measuring a difference between the hitting position of the ball and the center core position of the bat when the ball is hit with the bat actually. More specifically, there is provided a deviation measuring apparatus for measuring the degree of deviation between the center core position of a baseball bat and the hitting position of a ball by the bat, comprising: a high speed camera for photographing a condition in which the bat strikes the ball; and computing means for obtaining a distance of a difference between the center core position of the bat and the hitting position of the ball.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a deviation measuring apparatus.

2. Description of the Related Art

The bat used for rubber-ball baseball, hardball baseball and softball includes a variety of types depending on its weight, length, size, shape and the like. On the other hand, a batter can select his most suitable bat corresponding to his weight, height, physical force and the like.

Unless a bat suits for a batter, when the batter hits a ball, the ball is likely to be hit at a place deviated from its center core and as a consequence, likely the ball does not fly over an expected distance or the ball does not fly in an expected direction. Thus, selection of a bat fitting to a batter is extremely important for achieving expected batting.

Although conventionally, generally a customer purchases the bat according to an advice from a clerk of sports shop, it is substantially hard to select a bat fitting to the customer because there is no method for selecting a bat fitting to the customer objectively.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-described conventional problems and an embodiment of the invention may provide a deviation measuring apparatus which is helpful for customer's selecting a bat capable of bringing a ball hitting position to near the center core of the bat by measuring a difference between the ball hitting position and the bat center core position when the ball is hit with the hat actually and correcting his batting form.

To achieve the above feature, according to a first aspect of the invention, there may be provided a deviation measuring apparatus for measuring the degree of deviation between the center core position of a baseball bat and the hitting position of a ball by the bat, comprising: a high speed camera for photographing a condition in which the bat strikes the ball; and a computing means for obtaining a distance of a difference between the center core position of the bat and the hitting position of the ball.

According to a second aspect of the invention, there is provided a deviation measuring apparatus for measuring the degree of deviation between the center core position of a baseball bat and the hitting position of a ball by the bat, comprising: a high speed camera for photographing a condition in which the bat strikes the ball; a detecting means for detecting an impact timing of the ball by the bat; and a computing means for obtaining a distance of a difference between the center core position of the bat and the hitting position of the ball based on a picture of the high speed camera at the time of the impact.

According to a third aspect of the invention, there is provided the deviation measuring apparatus according to the first or second aspect wherein the ball is set statically.

According to a fourth aspect of the invention, there is provided the deviation measuring apparatus according to the first or second aspect wherein the ball is thrown.

According to a fifth aspect of the invention, there is provided the deviation measuring apparatus according to the first or second aspect wherein the detecting means is provided in the ball or the bat for detecting the impact timing of the ball.

According to a sixth aspect of the invention, there is provided the deviation measuring apparatus according to the first or second aspect wherein the high speed camera is provided above the hitting position of the ball by the bat.

According to a seventh aspect of the invention, there is provided the deviation measuring apparatus according to the first or second aspect wherein the high speed camera is provided below the hitting position of the ball.

According to an eighth aspect of the invention, there is provided a deviation measuring apparatus comprising: a high speed camera for photographing a condition in which the ball is hit by the bat from sideway; and

a computing means for obtaining the degree of deviation in the vertical direction between the position of the bat and the hitting position of the ball based on a picture of the high speed camera.

The first aspect of the invention enables to select a bat capable of bringing the hitting position of the ball to near the center core position of the bat or correct a batting form of a batter by measuring a difference between the impact position of the ball and the center core position when the ball is hit with the bat actually.

In addition to the effect possessed by the first aspect, the second aspect of the invention enables to detect a picture of a moment in which the bat hits the ball immediately with the detecting means to select a bat fitting to each batter easily or correct the batting form of the batter.

In addition to the effect possessed by the first aspect or second aspect, the third aspect of the invention enables to select a bat suitable for each batter or correct a batting form of the batter by hitting a ball placed statically.

In addition to the effect possessed by the first aspect or second aspect, the fourth aspect of the invention enables to select a bat suitable for each batter or correct a batting form of the batter by hitting a thrown ball.

In addition to the effect possessed by the first aspect or second aspect, the fifth aspect of the invention enables to detect a moment in which the ball is hit with the bat by providing the detecting means in the ball or the bat.

In addition to the effect possessed by the first aspect or second aspect, the sixth aspect of the invention enables to detect a moment in which the ball is hit with the bat from above the batter with the high speed camera.

In addition to the effect possessed by the first aspect or second aspect, the seventh aspect of the invention enables to detect a moment in which the ball is hit with the bat from below the batter with the high speed camera.

The eighth aspect of the invention enables to select a bat suitable for each batter or correct a batting form of the batter by measuring the degree of a difference in vertical direction between the center core position of the bat and the hitting position of the ball.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:

FIG. 1 is a diagram showing a moment in which a ball is hit with a bat;

FIG. 2 is a side view of the deviation measuring apparatus;

FIG. 3 is a configuration diagram of computing means;

FIG. 4 is a side view of a bat indicating the vibration of the bat;

FIG. 5 is a flow chart;

FIG. 6 is a picture taken with a high speed camera;

FIG. 7 is a picture taken with a high speed camera;

FIG. 8 is a picture taken with a high speed camera;

FIG. 9 is a picture taken with a high speed camera;

FIG. 10 is a picture taken with a high speed camera; and

FIG. 11 is a drawing for obtaining a distance of difference between the center core position of the bat and a ball hitting position;

FIG. 12 is an indicated content of a display means;

FIG. 13 is a side view of a deviation measuring apparatus (second embodiment);

FIG. 14 is a flow chart (second embodiment);

FIG. 15 is a side view of the deviation measuring apparatus (third embodiment);

FIG. 16 is a flow chart (third embodiment);

FIG. 17 is a side view of the deviation measuring apparatus (fourth embodiment);

FIG. 18 is a flow chart (fourth embodiment); and

FIG. 19 is a diagram showing the degree of the deviation in the vertical direction between the center core position of the bat and the ball hitting position (fifth embodiment).

DESCRITPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-12 show a first embodiment. The deviation measuring apparatus of this embodiment searches for a distance d as a difference between a center core position 1 of a hitting bat B and a hitting position 2 when a batter hits the ball K as shown in FIG. 1.

FIG. 2 shows a side view of the deviation measuring apparatus 3. According to the first embodiment, the ball K is set in a static state in which it is placed on a tee 4. The tee 4 is adjustable vertically and can be adjusted to a height suitable for a batter.

As shown in FIG. 2, the deviation measuring apparatus 3 comprises a high speed camera 5 and an computing means 6. The high speed camera 5 is a device for photographing a condition in which the bat B hits the ball K. The high speed camera 5 is disposed just above the tee 4 to photograph a moment in which the ball K placed on the tee 4 is hit by the bat B from above. The high speed camera 5 can be constructed with a CCD camera.

The computing means 6 is means for obtaining a distance d, which is a difference between the center core position of the bat B and the hitting position 2 of the ball K by arithmetic operation and the computing means 6 can be constituted of a personal computer.

As shown in FIG. 2, the high speed camera 5 is disposed just above the tee 4 in a condition in which it is supported by a camera supporting base 7. The camera supporting base 7 comprises a base 8, a support 9 and a camera mounting portion 10.

The computing means 6 comprises a memory 11 and a computing portion 12 as shown in FIG. 3. The memory 11 memorizes image information taken by the high speed camera 5. The computing portion 12 is means for obtaining a distance d, which is a difference between the center core position 1 of the bat B and the hitting position 1 of the ball K. The computing means 6 includes a display means 13 as well as the memory 11 and the computing portion 12 and is capable of displaying a picture taken by the high speed camera 5. The display means 13 can be constituted of a display of the personal computer. The high speed camera 5 and the computing means 6 are actuated by a measuring start switch (not shown). The high speed camera 5 terminates photographing with a batting end switch (not shown).

Next, a center core position 1 of the bat B will be described with reference to FIG. 4. Generally, when the ball K collides with the bat B, the bat B vibrates as shown in FIG. 4 so that a loop H and nodes, P1 and P2 are generated in the bat B. The loop H is a portion which vibrates largely when the ball K strikes the bat B. The nodes P1 and P2 are portions which do not vibrate when the ball K strikes the bat B. Thus, by hitting the ball at the position of the nodes P1 and P2, the ball K can be hit back effectively with a least loss. Although the nodes P1 and P2 are generated at each of a front end of the bat B and a grip G, only a node is generated at the front end of the bat B. Thus, the positions of the nodes P1 and P2 of each bat B can be defined clearly.

According to an embodiment of the present invention, the position P1 of the node generated at the front end of the bat B is defined as the center core position 1. The center core position 1 is a position inherent of each bat B which is determined depending on the length, weight, shape and the like of the bat B and the center core position 1 of each bat B changes delicately along the length direction of the bat 1.

To hit the ball K effectively at the center core position 1 of the bat B, each batter needs to select an appropriate bat B to himself because various conditions including the height, physical force, length of arm, batting form and the like differ depending on each batter. Thus, according to this embodiment, the batter hits the ball actually and by measuring a difference between the center core position 1 of the bat and a hitting position 2 of the ball at that time, it enables the customer to select a bat B which is capable of bringing the hitting position 2 of the ball to near the center core position 1 of the bat or correct his batting form.

Next, the operation of the memory 11 and computing portion 12 will be described with reference to FIG. 5. First, in step S1, the entire system is started by operating the measurement start switch.

In step S2, the high speed camera 5 starts photographing continuously. In step S3, picture information taken by the high speed camera 5 is stored in the memory 11. FIG. 6 shows a picture taken by the high speed camera 5 at this time. Because the batter does not yet start a batting motion at this time, the bat B is not photographed on an picture shown in FIG. 6 but only the ball K placed on the tee is photographed.

Next, the batter starts batting in step S4 in FIG. 5. FIG. 7 shows a picture taken by the high speed camera 5 at this time. FIG. 7 shows a condition in which the bat B is still quite apart from the ball K placed on the tee 4.

Next, a picture shown in FIG. 8 expresses the ball K placed on the tee 4 and the bat B approaching the ball K gradually. FIG. 9 shows a moment in which the bat strikes the ball K. FIG. 10 indicates a condition in which the ball K flies forward apart from the bat B. Respective pictures indicated in FIGS. 6-10 are memorized as image information in the memory 11 and displayed on the display means 13.

Next, when the batter finishes batting in step S5 in FIG. 5the batting end switch is operated to terminate photographing of the high speed camera 5 in step S6.

Next, a picture photographing both the bat B and the ball K is extracted from the image information pieces memorized in the memory 11 in step S7. That is, pictures shown in FIGS. 7-10 are extracted.

In this case, the background of the picture and bat B are expressed in black and the ball K is expressed in white as indicated in the same Figure. On the other hand, two white center core position identifying lines R1, R2 are provided at positions sandwiching the center core position 1 and by converting the image information to binary data, the center core position 1 of the bat B and the ball K can be distinguished from the back ground. That is, in the image information, the background information and the bat B are recognized as a set of 0 and the ball K is recognized as a set of 1. The center core position 1 of the bat B can be recognized such that it is sandwiched by the sets of 1 of the two center core identifying lines R1, R2. Then, upon batting, a condition in which the center core position 1 sandwiched by the two center core position identifying lines R1, R2 of the bat B approaches the ball K and strikes the ball K is photographed. In the meantime, although the bat B is expressed in black and the same color as the background in the above description, it is permissible to express the bat B in white (or color inherent of that product) and affix a black tape to the center core position 1 to make the bat B, the ball K and the center core position 1 recognized. By giving a mark to the front end of the bat B instead of affixing the tape to the center core position 1 and registering data about a distance N between the center core position 1 of each bat B and the mark at the front end preliminarily, the center core position 1 can be synthesized on a virtual screen, so that the distance between the center core position 1 and the ball K can be obtained also.

Next, a picture in which the distance between the bat B and the ball K is the shortest, that is, a picture shown in FIG. 9 is selected form pictures shown in FIGS. 7-10 extracted as described previously, that is, pictures photographing both the bat B and the ball K, in step S8. Hereinafter, a distance d which is a difference between the center core position 1 of the bat B and the hitting position 2 of the ball K is obtained based on the picture shown in FIG. 9 selected in this way.

First, the center core position 1 of the bat B is obtained in step S9. That center core position 1 has been already known as described in FIG. 4. Additionally, the position of the ball K is obtained. Next, a method for obtaining a distance d, which is a difference between the center core position 1 of the bat B and the hitting position 2 of the ball K, that is, the amount of a deviation will be explained with reference to FIG. 11.

The X axis and Y axis intersect each other at a center 0 of a screen shown in FIG. 11. In the same FIG. 11, the bat B indicated with a solid line indicates the bat B at a position shown in FIG. 8 and the bat B indicated with a two-dot and dash line indicates the bat B at a position shown in FIG. 9. The center core position 1 of the bat B is expressed as a line intersecting an axis L of the bat B at a predetermined distance N from the front end of the bat B. Assume that a midpoint of a line indicating the center core position 1 of the bat B in FIG. 8 is A(x1, y1) and that a midpoint of a line indicating the center core position 1 of the bat B in FIG. 9 is B (x2, y2). If it is assumed that the bat B moves linearly when striking the ball K, a line T which is an extension of a trajectory of the center core position 1 of the bat B can be obtained according to a formula 1. y=(y2−y1)/(x2−x1)x+(x2y1−x1y2)/((x2−x1)   (Formula 1)

Then, assuming that the central coordinate of the ball is Q(s, t), a distance between the line T and the central coordinate of the ball, namely, a distance d which is a difference between the center core position 1 of the bat B and the hitting position 2 of the ball K, that is, the amount of deviation is expressed by a following formula 2. d=|as−t+b|/√{square root over ( )}(a ²+1)   (Formula 2) where a=(y2−y1)/(x2−x1), b=(x2y1−x1y2)/(x2−x1) The amount of the deviation is displayed on the computing means 6 shown in FIG. 3 in step S12.

FIG. 12 is a screen of the display means 13 which displays a result of measurement of the deviation as described previously, this screen displaying results of measurement of the deviation using a variety of the bats having different factors in the center core position, length, weight and the like. Because the result of the deviation when using each bat B can be visually checked through the screen, each batter can retrieve a bat fitting to himself by comparing with other bats. Of bats B shown in FIG. 12, it can be recognized that a bat B having a name XXOO has the least amount of deviation and is suitable.

By obtaining the degree of a difference between the center core position 1 of the bat B and the hitting position 2 of the ball K and then correcting the batting form of a batter, as mentioned above, the center core position 1 of the bat B can be brought near the hitting position 2 of the ball K gradually. The direction of a hit ball and a fly distance of the ball can be estimated depending on a head speed of the bat B, speed of a hit ball, impact rate, hitting angle and the like. In this case, this apparatus can be used for guiding the batter for a fly distance of the ball if the ball is hit at the center core position of the bat B.

FIGS. 13 and 14 show the second embodiment. According to the second embodiment, a vibration sensor is buried in the tee 4 and an impact timing is detected by detecting a vibration of a moment in which the ball K is hit. By reading picture information photographed at the time of the impact from the memory 11 immediately, the distance d, which is a difference between the center core position 1 of the bat B and the hitting position 2 of the ball K may be measured immediately. A detecting means for detecting the moment in which the bat B hits the ball K is constituted by the vibration sensor. FIG. 14 shows a flow chart of a third embodiment.

After the measurement start switch is operated in step Si in FIG. 14, batting is started in step S2. At the same time when the vibration sensor buried in the tee 4 detects the vibration in step S21 as described above, the high speed camera 5 is actuated in step S22 and its photographed picture is memorized in the memory 11 in step S23. Hereinafter, step S9-step S12 are executed like the first embodiment. Because if the response of the high speed camera 5 is excellent, the high speed camera 5 can photograph a condition at the moment when the bat B hits the ball K immediately after the detecting means detects that moment, the distance d which is the difference between the center core position 1 of the bat B and the hitting position 2 of the ball K can be measured only by photographing just a picture at that moment with the high speed camera 5. In the meantime, the detecting means may be provided in the ball K or bat B in order to detect a moment when the bat B hits the ball K.

FIGS. 15 and 16 show a third embodiment. The feature of this third embodiment is that first, second sensors 21 and 22 are provided along the direction in which the hit ball K flies. Each of these sensors 21, 22 comprises a light emitting portion 23 and a light receiving portion 24. Laser beam R outputted from the light emitting portion 23 is received by the light receiving portion 24.

Next, the flow chart of the third embodiment will be explained with reference to FIG. 16. Description of step S1-step S4 is omitted because it is the same as the first embodiment.

If the hit ball K is detected by the first, second sensors 21 and 22 in step S21 and S22, photographing by the high speed camera 5 is terminated in step S23.

Next, an impact timing of the ball K by the bat B is obtained in step S24. That impact timing is obtained as follows. First when the two sensors 21 and 22 detect the hit ball K each, a difference of time between times in which the hit ball K is detected by the sensors 21 and 22 is obtained. After that, a speed of the hit ball K is obtained by dividing a distance between the two sensors 21 and 22 by that time difference. Then, a time taken until the hit ball K reaches the first sensor from the tee 4 after it is hit can be obtained by dividing a distance between the first sensor 21 and the tee 4 by the speed of the hit ball 4. Thus, by returning to a time in which the hit ball K arrives at the first sensor 21 from the tee 4 from the time in which the hit ball K is detected by the first sensor 21, the impact timing of the ball K by the bat B can be obtained. Thus, image information photographed at the impact timing can be read out from the memory immediately.

According to the third embodiment, the distance d which is the difference between the center core position 1 of the bat B and the hitting position 2 of the ball K can be measured immediately by reading out image information photographed at the impact timing from the memory 11.

FIGS. 17 and 18 show a fourth embodiment. The feature of the fourth embodiment is that as shown in FIG. 17, when a batter hits back the ball K thrown from a pitching machine 31, the distance d which is the difference between the center core position 1 of the bat B and the hitting position 2 of the ball K is measured. According to this fourth embodiment, the first and second sensors 21, 22 are disposed between the pitching machine 31 and the batter.

Next, the operation of the computing means 6 will be explained based on FIG. 18. First, the entire system is actuated by operating the measurement start switch in step S31. The pitching machine 31 throws the ball K in step S32. The high speed camera 5 starts photographing in step S33 and image information photographed is stored in the memory 11 in step S34.

Next, the ball K thrown by the pitching machine 31 reaches the position of the batter while sensed by the second and first sensors 22 and 21 in step S35 and step S36. Then, the ball is hit back by the batter in step S37. After the ball K hit back by the batter is detected by the first sensor 31 in step S38, it is detected by the second sensor 22 in step S39. By detecting the hit ball K by the second sensor 22 in step S39, the operation of the high speed camera 5 is stopped in step S40.

Because steps subsequent to step S7 are the same as the first embodiment, description thereof is omitted. Although in the above embodiment, a case where the ball K thrown from the pitching machine 31 is hit back by the batter, needless to say, this embodiment can be applied to a case where the batter hits a ball thrown by a human instead of the pitching machine 31.

According to the fourth embodiment, when the batter hits back a thrown ball, the distance d which is the difference between the center core position 1 of the bat B and the hitting position 2 of the ball K can be measured.

FIG. 19 shows a fifth embodiment. The feature of this embodiment lies in obtaining the distance d which is the difference in the vertical direction between the center core position 1 of the bat B and the hitting position 2 of the ball K. Thus, the high speed camera 5 photographs a moment when the ball K is hit by the bat B from sideway of the batter. Then, the computing means 6 obtains the degree of the difference in the vertical direction between the center core position 1 of the bat B and the hitting position 2 of the ball K based on information of a picture photographed by the high speed camera 5.

FIG. 19 shows a picture taken from sideway of the batter. In the same Figure, the center core position 1 of the bat B corresponds to axis of the bat. Assume that the ball K is placed on the tee 4. On the other hand, the direction in which the bat approaches the ball K for hitting is indicated with an arrow. Reference numeral 2 indicates an impact position in which the bat B hits the ball K. Then, assuming that an angle formed by a line connecting the hitting position 2 with the center core position 1 of the bat B with respect to the advancement direction of the bat B is θ, this θ corresponds to the degree of the deviation in the vertical direction between the center core position 1 of the bat B and the hitting position 2 of the ball.

As a consequence, the batting form can be corrected or each batter can select a bat fitting to himself based on the degree of the deviation in the vertical direction obtained in this way.

While the preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the appended claims. 

1. A deviation measuring apparatus for measuring a degree of deviation between a center core position of a baseball bat and a hitting position of a ball by the bat, comprising: a high speed camera for photographing a condition in which the bat strikes the ball; and computing means for obtaining a distance of a difference between the center core position of the bat and the hitting position of the ball.
 2. A deviation measuring apparatus for measuring a degree of deviation between a center core position of a baseball bat and a hitting position of a ball by the bat, comprising: a high speed camera for photographing a condition in which the bat strikes the ball; detecting means for detecting an impact timing of the ball by the bat; and computing means for obtaining a distance of a difference between the center core position of the bat and the hitting position of the ball based on a picture of the high speed camera at the impact timing.
 3. The deviation measuring apparatus according to claim 1 wherein the ball is set statically.
 4. The deviation measuring apparatus according to claim 1 wherein the ball is thrown.
 5. The deviation measuring apparatus according to claim 1 wherein the detecting means is provided in the ball or the bat for detecting the impact timing of the ball.
 6. The deviation measuring apparatus according to claim 1 wherein the high speed camera is provided above the hitting position of the ball by the bat.
 7. The deviation measuring apparatus according to claim 1 wherein the high speed camera is provided below the hitting position of the ball.
 8. A deviation measuring apparatus comprising: a high speed camera for photographing a condition in which the ball is hit by the bat from sideway; and computing means for obtaining a degree of deviation in a vertical direction between a position of the bat and the hitting position of the ball based on a picture of the high speed camera.
 9. The deviation measuring apparatus according to claim 2 wherein the ball is set statically.
 10. The deviation measuring apparatus according to claim 2 wherein the ball is thrown.
 11. The deviation measuring apparatus according to claim 2 wherein the detecting means is provided in the ball or the bat for detecting the impact timing of the ball.
 12. The deviation measuring apparatus according to claim 2 wherein the high speed camera is provided above the hitting position of the ball by the bat.
 13. The deviation measuring apparatus according to claim 2 wherein the high speed camera is provided below the hitting position of the ball. 